The paper presents the study of a new compressor for household appliances, developed through a virtual simulation system, with Simulink and Adams software. Linear compressor has a linear motor coupled to a mechanical system: a piston and a spring. The advantage of this compressor respect to a standard reciprocating compressor is due to the high reduction of energy losses and variable capacity p...

Digital linear filters are used in a variety of applications (sound treatment, control/command, etc.), implemented in software, in hardware, or a combination thereof. For safety-critical applications, it is necessary to bound all variables and outputs of all filters. We give a compositional, effective abstraction for digital linear filters expressed as block diagrams, yielding sound, precise bo...

We discuss the use of the formal theory of differential equations in the numerical analysis of general systems of partial differential equations. This theory provides us with a very powerful and natural framework for generalising many ideas from differential algebraic equations to partial differential equations. We study in particular the existence and uniqueness of (formal) solutions, the meth...

The method originally developed by Kalnajs for the numerical linear stability analysis of round galactic disks is implemented in the regimes of non-analytic transformations between position space and angle-action space, and of vanishing growth rates. This allows effectively any physically plausible disk to be studied, rather than only those having analytic transformations into angle-action spac...

The lattice Boltzmann equations for the linear diffusion modeling in cases of D2Q5, D2Q7 and D2Q9 lattices are considered. Families of the numerical schemes with the dependence on scalar parameter are introduced. The stability analysis of schemes is performed in parameter space. The stability is studied numerically by von Neumann method. Optimal parameter values for the presented families are d...

In this report the ray-gridding approach, a new numerical technique for the stability analysis of linear switched systems is presented. It is based on uniform partitions of the state-space in terms of ray directions which allow refinable families of polytopes of adjustable complexity to be examined for invariance. In this framework the existence of a polyhedral Lyapunov function that is common ...

at the current iterate x ∈ Rn. In practice, we find that the bulk of computational resources (memory, time) consumed by these algorithms is spent constructing and solving these linear systems, and not in the higher-level algorithmic details. That is not to say that the higher-level details do not impact performance; for example, algorithmic improvements could result in a reduction in the number...

Piecewise linear interpolation of 2D scattered vector data is a classical, simple and fast scheme to process the discrete information provided by experiments or numerical simulations. Nevertheless, its major drawback is its low order that prevents satisfying approximation of non linear behaviors. For topology-based methods in particular, commonly applied in vector field visualization, it often ...

For strongly directed anisotropic processes such as coherence-enhancing di usion ltering it is crucial to use numerical schemes with highly accurate directional behavior. We show that this is not possible in a satisfactory way when discretizations are limited to 3 3 stencils. As a consequence, we investigate a novel algorithm based on 5 5 stencils. It utilizes recently discovered di erentiation...

In this paper, based on the kinematic accuracy theory and matrix-based system reliability analysis method, a practical method for system reliability analysis of the kinematic performance of planar linkageswith correlated failuremodes is proposed. The Taylor series expansion is utilized to derive a general expression of the kinematic performance errors caused by random variables. A proper limit ...